Why do things "burn up" in the atmosphere?

Answer 1

The short simple answer is: air resistance. I assume you are referring to
"things" like meteorites and old satellites. These have speeds of over
10,000 MPH, and when they enter the Earth's upper atmosphere, they experi-
ence frictional forces with the air molecules, which, in turn, generates
vast amounts of heat. In everyday life we do not usually associate friction
with heat but remember the old Boy Scout (and indigenous peoples') trick of
rubbing two sticks together to make fire.

Answer 2

I see this type of question answered incorrectly all the time. It is not primarily friction that causes things to burn up in the atmosphere. While there is some friction, it is only a minor contributor to heat. The right answer is that when an object enters the atmosphere at high speed, it compresses the air in front of it. Compressing the air heats it up. This is what causes things to burn up in the atmosphere.

Answer 3

The objects that are coming into Earth's atmosphere are moving at very high speeds (due to the fact that space is a near vacuum so there is no friction). Once they start to come in contact with matter, friction starts to create heat and things start to burn up.

Answer 4

The answer is quite simple.
The FRICTION caused due to air resistance in the atmosphere makes the objects to burn-up in the atmosphere.

A good example is Meteor.